How to Upgrade, Repair, Disassemble a Canon Printer

Do you need to upgrade or repair your Canon printer? Here is a collection of free take apart instructions, disassembly pictures, cleaning advice, upgrade and repair manuals, as well as do-it-yourself (DIY) tips and tricks for BubbleJet, Pixma printers and for ink or toner cartridges. If you have written a guide yourself (or if you know of a maintenance tutorial not linked here), please submit a new entry.

Canon Bubblejet BJC-6500	Illustrated take apart and re-assembly instructions.
Canon Pixma iP3000, iP4000, iP5000, iP6000D, iP8500	Five easy steps to enable the Canon USA models to print directly to CD or DVD.
Canon Pixma iP3000/4000/5000	An illustrated print head cleaning guide.
Canon Pixma iP4000	How to modify the printer to print on CDs and DVDs. Resetting the ink-waste overflow counter.
Canon Pixma iP4000 (ip3000, iP4000R, iP5000)	Panic: "Waste ink tank full" this guide will show you how to change the waste ink collector of the printer and how to reset its respective counter.

Manufacturer Information, Customer Service

Hardware Maintenance Manual, User Guide, Service Manual

As far as I know Canon doesn't provide free service manuals.